Posts, Pages, Backlinks, Anchor Text

OK, starting at the top:

1. Pages are the best place to situate keywords you want to rank for over a long period of time where content is not changing extensively as your site matures. Posts, because of the way the CMS stores them, have a kind of moving-target URL as they descend into your site over time, so they are better for content you want to get noticed but not necessarily for serious ranking target pages.

So, pages (which have static URLs that don't ever move) for ranking targets and posts for useful information and for backlinking internally to Pages. It's a bit simplistic, but a good place to start structurally. Keep in mind though that WordPress, if that's what you're using, is pinging primarily for your blog posts, not your pages. So do a good job of internal links from posts.

2. Regarding use of keywords, you don't have to make a choice between what keywords you use in backlinks and what you use on the page. You can use keywords in both places. In fact, this is better, because there will be more relevancy between your link anchor text and your on-page content. Those extra related keywords will help Google to best understand your page. Then you can vary up the anchor text on backlinks, with keyword modifiers to give your backlinks some extra punch. In fact, the link anchor text variations will actually help your site rank better for different actual keyword combinations.

3. Regarding Google updating in the index - yes, any page you change the content on has the potential to be re-crawled and updated in the index. It's just a matter of when Google gets around to checking it out again. The more regular content you add to your site, posting a post or two daily, regularly, will help coax Google to crawl your site more often (if the content is good and not spammy), and then increases the chance they'll find your changed content and re-index with new data.

Those are all extremely similar keywords, so I'd consider them variations on the main keyword and incorporate all 3 in the same page. You could then build backlinks to that page using all the variations. In fact, that's a good practice overall.

I kind of agree with esdavis about the main keywords built around pages. I find this a limiting strategy, though. Most of my traffic (in the early days of a site, which I guess yours is, comes from the longer tails, which are best represented in posts, imo.
Those posts can always (and should always) contain anchor text internal links to your pages). However, they always exist as posts and rank well in the search engines with minimal backlinks. I still find that individual posts (en masse) make up the bread and butter of my site and serve to reinforce the main keyword 'pages'.

Although they are tough keywords, personally I would make fully on-page optimised posts for each of those three keyword phrases, include a few LSI keywords in the same post and then backlink them over time to see them rise.

The backlinks would target the exact keyword phrase around 50% of the time as anchor text and would split the remaining anchor text backlinks between the LSI or any other related keyword phrases - chuck in a few unrelated for good measure.

With a few "click here" "dave smith" and other backlinks thrown in. I would make those backlinks a mixture of the best social bookmark sites, the best high pr blog comments from minimal outbound link comments in .com, .edu, .ac.uk and anywhere else. I would try to get a couple of UNIQUE .govs and I would try to get a Wikipedia link from a related page with salient information or just hope for the best that it doesn't get deleted (or create your own wikipedia page if you can.)

I'd also throw in a well-written press release and get it syndicated to the best PR submission sites that you can afford (or do the best free ones). And chuck in some links from a few online newspapers, preferably those that appear in Google News.

As if that wasn't enough, I would add ezine articles and other decent article sites into the mix, a few 2.0 sites, How-to sites, and some videos backlinking to the site from Youtube, etc

Finally, I would spend a little time on mass social bookmarking to Facebook, Twitter, Reddit, Digg, Stumbleupon et al.

You can always throw in some RSS submissions and directory submissions.

For long tail posts go ridiculously down to the long sentence. So I sell "shiny orange football boots" - I would make posts like:

"Where Can I Find The Best Shiny Orange Football Boots"
or "Who Sells the Cheapest Shiny Orange Football Boots online"

I find that phrasing questions as a buyer (and ranking those phrases) has the best results for me. Talk about 'I' and not 'you' - people don't search for 'you' very often.

I guess it comes down to how you structure your sites. I prefer a main static page that ranks well for 1 MAJOR keyword (your EMD) and several smaller keywords (but still good longer term targets). I then try to back that up with many, many blog posts.

Maybe I haven't found the best set-up yet, but I find that too many "pages" makes this set-up too messy.

Hey - I'm still learning here. I'm as interested as you as to what others think works. I know I am having success with my personal method but I'm all for learning.

More pages and posts on a site is usually better, but with words that are very similar, you'll have to do some hard thinking to keep the content on 2 separate pages from looking practically the same.

If you focused the different pages on slightly longer-tail phrases than your core, you could slip in more LSI type keywords. But personally I try to keep ranking targets unique compared to other ranking pages, in order to not have the pages competing against each other.

I'd do more keyword research on those work from home job type keywords rather than trying to do a keyword rich page for each phrase, since they are so closely related.